I know its not a M14 but the T20 was an evolutionary step between the Garand and M14. In case you dont know what a T20 was, it was an SA experimental select fire, box magazine fed Garand rifle. I created my mini30/m14 last year so I decided why not build a mini 300blkout/ T20 garand. I had Accuracy Systems rebarrel my mini 14 and shape the bbl to garand bbl contours. Just got it back and have been inletting the action, filling and shaping the stock. I removed the splines from a demilled gas cylinder so that it would slide over the bbl and duck taped it to the bbl yesterday so Id have a front sight, installed a mag and fired 8 manually cycled rds through it. Magazine fed fine and locked the bolt. Even hit my cowboy steel. When I get the wood right Ill send it to Shuffs to have the splines and threads cut at the muzzle for a good gas cylinder. Last will be connecting the cut ruger op rod to the cut garand op rod. Ive got the distinctive muzzle brake almost built. Its coming together.

Finally found a kinda local smith to do my bbl work. He’s done the gas cylinder machining and we talked last week and got the op rod mods planned. Next month we’ll get together with a bunch of my handloads and factory stuff and see what happens. Then I can finish the stock work. Still haven’t decided if I want to use my jbweld stock as a pattern and have another stock duplicated from it or just paint it with a WW2 pattern. After all it was an experimental rifle.

There is a complete chapter on all the T20, Full-Auto Garands, and all the other T-series rifles that led to the M14, in the revised Last Steel Warrior book.

Hardcover, lots of detailed color photos.

www.smallarmsreview.com

On the T-20 a modified BAR Box magazine was used, any idea of the spring rate. It was a heavier spring then used in the BAR, Correct?

The T-20 was basically a 30-06 box mag Garand? with F/A Capabilities

I'm not home, don't have the book in front of me, but as I can recall... The cyclic rate of the T20 was too fast to feed from a standard BAR magazine, a stiffer spring helped, but mags with the stiffer spring would not work reliably in a BAR. The Ordnance Dept did not want to issue two identical-appearing magazines that would only work in a BAR or a T20, not both.

There is a complete chapter on all the T20, Full-Auto Garands, and all the other T-series rifles that led to the M14, in the revised Last Steel Warrior book.

Hardcover, lots of detailed color photos.

www.smallarmsreview.com

On the T-20 a modified BAR Box magazine was used, any idea of the spring rate. It was a heavier spring then used in the BAR, Correct?

The T-20 was basically a 30-06 box mag Garand? with F/A Capabilities

I'm not home, don't have the book in front of me, but as I can recall... The cyclic rate of the T20 was too fast to feed from a standard BAR magazine, a stiffer spring helped, but mags with the stiffer spring would not work reliably in a BAR. The Ordnance Dept did not want to issue two identical-appearing magazines that would only work in a BAR or a T20, not both.

Another thanks for the T20 info. Fired my build last month but the op rod was still touching something so it wouldn’t completely cycle. Once we get the op rod moving free then we can tinker with the gas hole. Tweek this and tweek that. My smith is still working on it. I need give him a call this week.

After putting the gun together my smith got stumped and couldn’t get it ti cycle. I picked it up and started playing with it swapping out op rod springs and redoing his guide rod arrangement and yesterday got 8 rds of American Eagle to feed, fire and eject ok. His wag for a gas port was .070 which was too small so I opened it to .099 but while aguila ejected fine it wouldn’t strip the next rd so last night I opened it up to .111. More testing today.